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author | Michael Niedermayer <michaelni@gmx.at> | 2012-06-18 16:13:22 +0200 |
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committer | Michael Niedermayer <michaelni@gmx.at> | 2012-06-18 16:32:31 +0200 |
commit | 3a0a2f33a6c955823fa4fb12c0b49cd29a496659 (patch) | |
tree | 91b59638ce4de93e219c90ecf3637307e360e9ca | |
parent | 8c3514647e86f90dc4ac2c3b372aa2b3ae356cdb (diff) | |
download | ffmpeg-3a0a2f33a6c955823fa4fb12c0b49cd29a496659.tar.gz |
libavutil: add AV_QSORT()
about 2-5 times faster than gnu libcs qsort()
And should be 100% binary identical across platforms.
I will bump the version once the API is certainly stable and
everyone is happy with the API.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
-rw-r--r-- | libavutil/qsort.h | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/libavutil/qsort.h b/libavutil/qsort.h new file mode 100644 index 0000000000..ca66c5fb62 --- /dev/null +++ b/libavutil/qsort.h @@ -0,0 +1,86 @@ +/* + * copyright (c) 2012 Michael Niedermayer <michaelni@gmx.at> + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "common.h" + + +#define AV_QSORT(p, num, type, cmp) {\ + void *stack[64][2];\ + int sp= 1;\ + stack[0][0] = p;\ + stack[0][1] = p+num-1;\ + while(sp){\ + type *start= stack[--sp][0];\ + type *end = stack[ sp][1];\ + while(start < end){\ + if(start < end-1) {\ + int checksort=0;\ + type *right = end-2;\ + type *left = start+1;\ + type *mid = start + ((end-start)>>1);\ + if(cmp(start, end) < 0) {\ + if(cmp( end, mid) < 0) FFSWAP(type, *start, *mid);\ + else FFSWAP(type, *start, *end);\ + }else{\ + if(cmp(start, mid) < 0) FFSWAP(type, *start, *mid);\ + else checksort= 1;\ + }\ + if(cmp(mid, end) < 0){ \ + FFSWAP(type, *mid, *end);\ + checksort=0;\ + }\ + if(start == end-2) break;\ + FFSWAP(type, end[-1], *mid);\ + while(left <= right){\ + while(left<=right && cmp(left, end-1) > 0)\ + left++;\ + while(left<=right && cmp(right, end-1) < 0)\ + right--;\ + if(left <= right){\ + FFSWAP(type, *left, *right);\ + left++;\ + right--;\ + }\ + }\ + FFSWAP(type, end[-1], *left);\ + if(checksort && (mid == left-1 || mid == left)){\ + mid= start;\ + while(mid<end && cmp(mid, mid+1) >= 0)\ + mid++;\ + if(mid==end)\ + break;\ + }\ + if(end-left < left-start){\ + stack[sp ][0]= start;\ + stack[sp++][1]= right;\ + start = left+1;\ + }else{\ + stack[sp ][0]= left+1;\ + stack[sp++][1]= end;\ + end = right;\ + }\ + }else{\ + if(cmp(start, end) < 0)\ + FFSWAP(type, *start, *end);\ + break;\ + }\ + }\ + }\ +} |